/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.hadoop.hbase.wal;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertNull;
import static org.junit.Assert.assertTrue;

import java.io.IOException;
import java.util.HashSet;
import java.util.NavigableMap;
import java.util.Set;
import java.util.TreeMap;
import java.util.concurrent.ThreadLocalRandom;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hbase.HBaseClassTestRule;
import org.apache.hadoop.hbase.HBaseTestingUtil;
import org.apache.hadoop.hbase.HConstants;
import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.ServerName;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.ColumnFamilyDescriptorBuilder;
import org.apache.hadoop.hbase.client.RegionInfo;
import org.apache.hadoop.hbase.client.RegionInfoBuilder;
import org.apache.hadoop.hbase.client.TableDescriptor;
import org.apache.hadoop.hbase.client.TableDescriptorBuilder;
import org.apache.hadoop.hbase.regionserver.MultiVersionConcurrencyControl;
import org.apache.hadoop.hbase.testclassification.MediumTests;
import org.apache.hadoop.hbase.testclassification.RegionServerTests;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.hbase.util.CommonFSUtils;
import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
import org.junit.AfterClass;
import org.junit.Before;
import org.junit.BeforeClass;
import org.junit.ClassRule;
import org.junit.Rule;
import org.junit.Test;
import org.junit.experimental.categories.Category;
import org.junit.rules.TestName;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

@Category({ RegionServerTests.class, MediumTests.class })
public class TestFSHLogProvider {

  @ClassRule
  public static final HBaseClassTestRule CLASS_RULE =
    HBaseClassTestRule.forClass(TestFSHLogProvider.class);

  private static final Logger LOG = LoggerFactory.getLogger(TestFSHLogProvider.class);

  private static Configuration conf;
  private static FileSystem fs;
  private final static HBaseTestingUtil TEST_UTIL = new HBaseTestingUtil();
  private MultiVersionConcurrencyControl mvcc;

  @Rule
  public final TestName currentTest = new TestName();

  @Before
  public void setUp() throws Exception {
    mvcc = new MultiVersionConcurrencyControl();
    FileStatus[] entries = fs.listStatus(new Path("/"));
    for (FileStatus dir : entries) {
      fs.delete(dir.getPath(), true);
    }
  }

  @BeforeClass
  public static void setUpBeforeClass() throws Exception {
    // Make block sizes small.
    TEST_UTIL.getConfiguration().setInt("dfs.blocksize", 1024 * 1024);
    // quicker heartbeat interval for faster DN death notification
    TEST_UTIL.getConfiguration().setInt("dfs.namenode.heartbeat.recheck-interval", 5000);
    TEST_UTIL.getConfiguration().setInt("dfs.heartbeat.interval", 1);
    TEST_UTIL.getConfiguration().setInt("dfs.client.socket-timeout", 5000);

    // faster failover with cluster.shutdown();fs.close() idiom
    TEST_UTIL.getConfiguration().setInt("hbase.ipc.client.connect.max.retries", 1);
    TEST_UTIL.getConfiguration().setInt("dfs.client.block.recovery.retries", 1);
    TEST_UTIL.getConfiguration().setInt("hbase.ipc.client.connection.maxidletime", 500);
    TEST_UTIL.startMiniDFSCluster(3);

    // Set up a working space for our tests.
    TEST_UTIL.createRootDir();
    conf = TEST_UTIL.getConfiguration();
    fs = TEST_UTIL.getDFSCluster().getFileSystem();
  }

  @AfterClass
  public static void tearDownAfterClass() throws Exception {
    TEST_UTIL.shutdownMiniCluster();
  }

  @Test
  public void testGetServerNameFromWALDirectoryName() throws IOException {
    ServerName sn = ServerName.valueOf("hn", 450, 1398);
    String hl = CommonFSUtils.getRootDir(conf) + "/"
      + AbstractFSWALProvider.getWALDirectoryName(sn.toString());

    // Must not throw exception
    assertNull(AbstractFSWALProvider.getServerNameFromWALDirectoryName(conf, null));
    assertNull(AbstractFSWALProvider.getServerNameFromWALDirectoryName(conf,
      CommonFSUtils.getRootDir(conf).toUri().toString()));
    assertNull(AbstractFSWALProvider.getServerNameFromWALDirectoryName(conf, ""));
    assertNull(AbstractFSWALProvider.getServerNameFromWALDirectoryName(conf, "                  "));
    assertNull(AbstractFSWALProvider.getServerNameFromWALDirectoryName(conf, hl));
    assertNull(AbstractFSWALProvider.getServerNameFromWALDirectoryName(conf, hl + "qdf"));
    assertNull(AbstractFSWALProvider.getServerNameFromWALDirectoryName(conf, "sfqf" + hl + "qdf"));

    final String wals = "/WALs/";
    ServerName parsed = AbstractFSWALProvider.getServerNameFromWALDirectoryName(conf,
      CommonFSUtils.getRootDir(conf).toUri().toString() + wals + sn
        + "/localhost%2C32984%2C1343316388997.1343316390417");
    assertEquals("standard", sn, parsed);

    parsed = AbstractFSWALProvider.getServerNameFromWALDirectoryName(conf, hl + "/qdf");
    assertEquals("subdir", sn, parsed);

    parsed = AbstractFSWALProvider.getServerNameFromWALDirectoryName(conf,
      CommonFSUtils.getRootDir(conf).toUri().toString() + wals + sn
        + "-splitting/localhost%3A57020.1340474893931");
    assertEquals("split", sn, parsed);
  }

  private void addEdits(WAL log, RegionInfo hri, TableDescriptor htd, int times,
    NavigableMap<byte[], Integer> scopes) throws IOException {
    final byte[] row = Bytes.toBytes("row");
    for (int i = 0; i < times; i++) {
      long timestamp = EnvironmentEdgeManager.currentTime();
      WALEdit cols = new WALEdit();
      cols.add(new KeyValue(row, row, row, timestamp, row));
      log.appendData(hri,
        getWalKey(hri.getEncodedNameAsBytes(), htd.getTableName(), timestamp, scopes), cols);
    }
    log.sync();
  }

  /**
   * used by TestDefaultWALProviderWithHLogKey
   */
  private WALKeyImpl getWalKey(final byte[] info, final TableName tableName, final long timestamp,
    NavigableMap<byte[], Integer> scopes) {
    return new WALKeyImpl(info, tableName, timestamp, mvcc, scopes);
  }

  /**
   * helper method to simulate region flush for a WAL.
   */
  private void flushRegion(WAL wal, byte[] regionEncodedName, Set<byte[]> flushedFamilyNames) {
    wal.startCacheFlush(regionEncodedName, flushedFamilyNames);
    wal.completeCacheFlush(regionEncodedName, HConstants.NO_SEQNUM);
  }

  // now we will close asynchronously and will not archive a wal file unless it is fully closed, so
  // sometimes we need to wait a bit before asserting, especially when you want to test the removal
  // of numRolledLogFiles
  private void waitNumRolledLogFiles(WAL wal, int expected) {
    TEST_UTIL.waitFor(5000, () -> AbstractFSWALProvider.getNumRolledLogFiles(wal) == expected);
  }

  private void testLogCleaning(WALFactory wals) throws IOException {
    TableDescriptor htd =
      TableDescriptorBuilder.newBuilder(TableName.valueOf(currentTest.getMethodName()))
        .setColumnFamily(ColumnFamilyDescriptorBuilder.of("row")).build();
    TableDescriptor htd2 =
      TableDescriptorBuilder.newBuilder(TableName.valueOf(currentTest.getMethodName() + "2"))
        .setColumnFamily(ColumnFamilyDescriptorBuilder.of("row")).build();
    NavigableMap<byte[], Integer> scopes1 = new TreeMap<>(Bytes.BYTES_COMPARATOR);
    for (byte[] fam : htd.getColumnFamilyNames()) {
      scopes1.put(fam, 0);
    }
    NavigableMap<byte[], Integer> scopes2 = new TreeMap<>(Bytes.BYTES_COMPARATOR);
    for (byte[] fam : htd2.getColumnFamilyNames()) {
      scopes2.put(fam, 0);
    }
    RegionInfo hri = RegionInfoBuilder.newBuilder(htd.getTableName()).build();
    RegionInfo hri2 = RegionInfoBuilder.newBuilder(htd2.getTableName()).build();
    // we want to mix edits from regions, so pick our own identifier.
    WAL log = wals.getWAL(null);

    // Add a single edit and make sure that rolling won't remove the file
    // Before HBASE-3198 it used to delete it
    addEdits(log, hri, htd, 1, scopes1);
    log.rollWriter();
    waitNumRolledLogFiles(log, 1);

    // See if there's anything wrong with more than 1 edit
    addEdits(log, hri, htd, 2, scopes1);
    log.rollWriter();
    assertEquals(2, FSHLogProvider.getNumRolledLogFiles(log));

    // Now mix edits from 2 regions, still no flushing
    addEdits(log, hri, htd, 1, scopes1);
    addEdits(log, hri2, htd2, 1, scopes2);
    addEdits(log, hri, htd, 1, scopes1);
    addEdits(log, hri2, htd2, 1, scopes2);
    log.rollWriter();
    waitNumRolledLogFiles(log, 3);

    // Flush the first region, we expect to see the first two files getting
    // archived. We need to append something or writer won't be rolled.
    addEdits(log, hri2, htd2, 1, scopes2);
    log.startCacheFlush(hri.getEncodedNameAsBytes(), htd.getColumnFamilyNames());
    log.completeCacheFlush(hri.getEncodedNameAsBytes(), HConstants.NO_SEQNUM);
    log.rollWriter();
    waitNumRolledLogFiles(log, 2);

    // Flush the second region, which removes all the remaining output files
    // since the oldest was completely flushed and the two others only contain
    // flush information
    addEdits(log, hri2, htd2, 1, scopes2);
    log.startCacheFlush(hri2.getEncodedNameAsBytes(), htd2.getColumnFamilyNames());
    log.completeCacheFlush(hri2.getEncodedNameAsBytes(), HConstants.NO_SEQNUM);
    log.rollWriter();
    waitNumRolledLogFiles(log, 0);
  }

  @Test
  public void testLogCleaning() throws Exception {
    LOG.info(currentTest.getMethodName());
    Configuration localConf = new Configuration(conf);
    localConf.set(WALFactory.WAL_PROVIDER, FSHLogProvider.class.getName());
    WALFactory wals = new WALFactory(localConf, currentTest.getMethodName());
    try {
      testLogCleaning(wals);
    } finally {
      wals.close();
    }
  }

  private void testWALArchiving(WALFactory wals) throws IOException {
    TableDescriptor table1 =
      TableDescriptorBuilder.newBuilder(TableName.valueOf(currentTest.getMethodName() + "1"))
        .setColumnFamily(ColumnFamilyDescriptorBuilder.of("row")).build();
    TableDescriptor table2 =
      TableDescriptorBuilder.newBuilder(TableName.valueOf(currentTest.getMethodName() + "2"))
        .setColumnFamily(ColumnFamilyDescriptorBuilder.of("row")).build();
    NavigableMap<byte[], Integer> scopes1 = new TreeMap<>(Bytes.BYTES_COMPARATOR);
    for (byte[] fam : table1.getColumnFamilyNames()) {
      scopes1.put(fam, 0);
    }
    NavigableMap<byte[], Integer> scopes2 = new TreeMap<>(Bytes.BYTES_COMPARATOR);
    for (byte[] fam : table2.getColumnFamilyNames()) {
      scopes2.put(fam, 0);
    }
    WAL wal = wals.getWAL(null);
    assertEquals(0, AbstractFSWALProvider.getNumRolledLogFiles(wal));
    RegionInfo hri1 = RegionInfoBuilder.newBuilder(table1.getTableName()).build();
    RegionInfo hri2 = RegionInfoBuilder.newBuilder(table2.getTableName()).build();
    // variables to mock region sequenceIds.
    // start with the testing logic: insert a waledit, and roll writer
    addEdits(wal, hri1, table1, 1, scopes1);
    wal.rollWriter();
    // assert that the wal is rolled
    waitNumRolledLogFiles(wal, 1);
    // add edits in the second wal file, and roll writer.
    addEdits(wal, hri1, table1, 1, scopes1);
    wal.rollWriter();
    // assert that the wal is rolled
    waitNumRolledLogFiles(wal, 2);
    // add a waledit to table1, and flush the region.
    addEdits(wal, hri1, table1, 3, scopes1);
    flushRegion(wal, hri1.getEncodedNameAsBytes(), table1.getColumnFamilyNames());
    // roll log; all old logs should be archived.
    wal.rollWriter();
    waitNumRolledLogFiles(wal, 0);
    // add an edit to table2, and roll writer
    addEdits(wal, hri2, table2, 1, scopes2);
    wal.rollWriter();
    waitNumRolledLogFiles(wal, 1);
    // add edits for table1, and roll writer
    addEdits(wal, hri1, table1, 2, scopes1);
    wal.rollWriter();
    waitNumRolledLogFiles(wal, 2);
    // add edits for table2, and flush hri1.
    addEdits(wal, hri2, table2, 2, scopes2);
    flushRegion(wal, hri1.getEncodedNameAsBytes(), table2.getColumnFamilyNames());
    // the log : region-sequenceId map is
    // log1: region2 (unflushed)
    // log2: region1 (flushed)
    // log3: region2 (unflushed)
    // roll the writer; log2 should be archived.
    wal.rollWriter();
    waitNumRolledLogFiles(wal, 2);
    // flush region2, and all logs should be archived.
    addEdits(wal, hri2, table2, 2, scopes2);
    flushRegion(wal, hri2.getEncodedNameAsBytes(), table2.getColumnFamilyNames());
    wal.rollWriter();
    waitNumRolledLogFiles(wal, 0);
  }

  /**
   * Tests wal archiving by adding data, doing flushing/rolling and checking we archive old logs and
   * also don't archive "live logs" (that is, a log with un-flushed entries).
   * <p>
   * This is what it does: It creates two regions, and does a series of inserts along with log
   * rolling. Whenever a WAL is rolled, HLogBase checks previous wals for archiving. A wal is
   * eligible for archiving if for all the regions which have entries in that wal file, have flushed
   * - past their maximum sequence id in that wal file.
   * <p>
   */
  @Test
  public void testWALArchiving() throws IOException {
    LOG.debug(currentTest.getMethodName());

    Configuration localConf = new Configuration(conf);
    localConf.set(WALFactory.WAL_PROVIDER, FSHLogProvider.class.getName());
    WALFactory wals = new WALFactory(localConf, currentTest.getMethodName());
    try {
      testWALArchiving(wals);
    } finally {
      wals.close();
    }
  }

  /**
   * Ensure that we can use Set.add to deduplicate WALs
   */
  @Test
  public void setMembershipDedups() throws IOException {
    Configuration localConf = new Configuration(conf);
    localConf.set(WALFactory.WAL_PROVIDER, FSHLogProvider.class.getName());
    WALFactory wals = new WALFactory(localConf, currentTest.getMethodName());
    try {
      final Set<WAL> seen = new HashSet<>(1);
      assertTrue("first attempt to add WAL from default provider should work.",
        seen.add(wals.getWAL(null)));
      for (int i = 0; i < 1000; i++) {
        assertFalse(
          "default wal provider is only supposed to return a single wal, which should "
            + "compare as .equals itself.",
          seen.add(wals.getWAL(RegionInfoBuilder
            .newBuilder(TableName.valueOf("Table-" + ThreadLocalRandom.current().nextInt()))
            .build())));
      }
    } finally {
      wals.close();
    }
  }
}
